1 Introduction

Graylog Server enables you to monitor all activity in your network including established or rejected network connections. With Graylog you can centrally collect the syslog messages of your complete infrastructure, spot problems early and resolve issues faster. This eliminates the need to log in to multiple devices to parse plain text log files.

The KEMP LoadMaster is used to load balance the Graylog Server workload. The LoadMaster offers advanced Layer 4 and Layer 7 server load balancing, SSL Acceleration and a multitude of other advanced Application Delivery Controller (ADC) features. The LoadMaster intelligently and efficiently distributes user traffic among the application servers so that users get the best experience possible.

1.1 Document Purpose

This document provides the recommended LoadMaster settings used when load balancing the Graylog Server workload. The KEMP Support Team is available to provide solutions for scenarios not explicitly defined. The KEMP support site can be found at: https://support.kemptechnologies.com

1.2 Intended Audience

This document is intended to be read by anyone who is interested in configuring the LoadMaster to optimize the Graylog Server.

2 Template

KEMP has developed a template containing our recommended settings for this workload. You can install this template to help when creating Virtual Services, as it automatically populates the settings. This is quicker and easier than manually configuring each Virtual Service. If needed, changes can be made to any of the Virtual Service settings after using the template.

For more information and steps on how to import and use templates, refer to the Virtual Services and Templates, Feature Description on the KEMP Documentation Page.

For steps on how to manually add and configure each of the Virtual Services using the recommended settings, refer to the steps in this document.

3 Architecture

4 Configure the LoadMaster

The deployed Graylog Server environment determines which of the following setups is used.

4.1 Enable Subnet Originating Requests Globally

It is best practice to enable the Subnet Originating Requests option globally.

In a one-armed setup (where the Virtual Service and Real Servers are on the same network/subnet) Subnet Originating Requests is usually not needed. However, enabling Subnet Originating Requests should not affect the routing in a one-armed setup.

In a two-armed setup where the Virtual Service is on network/subnet A, for example, and the Real Servers are on network B - Subnet Originating Requests should be enabled on LoadMasters with firmware version 7.1-16 and above.

When Subnet Originating Requests is enabled, the LoadMaster will route traffic so that the Real Server will see traffic arriving from the LoadMaster interface that is in that network/subnet not the Virtual Service address.

When Subnet Originating Requests is enabled globally, it is automatically enabled on all Virtual Services. If the Subnet Originating Requests option is disabled globally, you can choose whether or not to enable Subnet Originating Requests on a per-Virtual Service basis.